Banking on Diversity: Have you saved a seed lately?

As plant diversity around the globe continues to dwindle, the value of seed banks is becoming increasingly apparent. Precious genes that have benefited us in the past, that may benefit us now, or that will benefit us at some time in the future, are being lost .

From seed... ...to seed

What is a seed bank? Think of a seed bank as you would a conventional savings bank.Instead of depositing money into a secure account, you deposit seeds into a secure storage facility.You might wish to withdraw some or all of the seeds at some point, just as you might plan to withdraw money from your savings account from time to time.Both the seeds and your money can be saved for some future need or emergency.

Why do we need seed banks?

As we've already noted, there may be some future need.That need might manifest itself in some form of natural or human-made disaster.Insect plagues, disease, drought, fires, war, climate change, and hybrid seeds (more about this later) are all a threat to the myriad plant varieties with whom we share our world.Saving and replanting seeds from threatened varieties not only protects food crops and rare plants but preserves our biodiversity.Experts predict that, by the end of the 21st Century, fully half of the world's plants will be doomed to extinction.

Seeds, as opposed to live plants, are an expedient and practically failsafe way to preserve gene pools for the long term.They are generally small in size, take up little space, are not difficult to handle, require very little maintenance, and, depending on the variety, may remain viable for long periods of time.Who's responsible for the seeds?Who decides which types of seeds should be stored and the method of storage?That important decision is made by the staffs and boards of the approximately 1,400 seed banks around the world.

The most famous bank at the moment is the Svalbard Global Seed Vault (also known as the "Doomsday Vault"), which opened on Feb. 26, 2008, and is located on the Norwegian island of Spitsbergen near the town of Longyearbyen.On that date it also received its first shipment of 100 million seeds, originating from more than 100 different nations.The actual facility is located deep inside an arctic mountain and is designed to survive any disaster, natural or man-made.It collects and organizes samples from seed banks all over the world and functions as a global repository and backup for those banks.All deposits remain the possession of the depositor.

Another important and well-known facility is the Millennium Seed Bank Project (MSBP), located at the Royal Botanical Gardens in Kew, UK.It was officially opened in November 2000 by Prince Charles.MSBP's long-term goal is to store the seeds of over 24,000 global species of plants.It currently houses the seeds of the country's entire native plant population.The MSBP collaborates with other seed banking organizations all over the world by sharing information and by providing assistance with seed collection.Seeds remain in a bank's country of origin, but the MSBP stores packets of those seeds for backup.

Both the Svalbard Vault and the MSBP are funded by public and corporate donations and by grants and endowments.

A third bank of importance is the Vavilov Institute of Plant Industry in St. Petersburg, Russia.Established in 1894, it's the oldest seed bank in the world and the only official seed bank in Russia.Seeds from hundreds of thousands of plant varieties make up its global collection.The bank is named for Nikolai Vavilov, who was one of the first scientists to understand the importance of crop diversity and played a major role in raising awareness of the importance of genetic conservation.

What kind of seeds are stored?The type of seeds stored in a seed bank varies with the mission of each bank. As we've already seen, the MSBP concentrates on the preservation of native plants. This is a particularly vital mission, since it's

We grow these heirloom flowers in our gardens. Links to information about each variety appear below.

estimated that one in every six known wild plants in the world is used for medical purposes.Other banks store seeds from food crops such as apples, barley, beans, carrots, coconuts, corn, eggplants, lentils, oats, peas, potatoes, rice, strawberries, sweet potatoes, and wheat.Still others store seeds of endangered species and heirloom varieties.Many store seeds from plants in all these categories.

Heirloom vegetables like those pictured are being lost at an alarming rate. Links to information about each variety appear in the column to the right

Heirloom vegetable varieties are rapidly decreasing in number. In Europe alone, it's estimated that over 2,000 varieties have been lost since the 1970s. This is due in large part to the introduction and popularity of hybrid vegetables, whose seeds cannot be used, since many of them don't come true to variety when saved and planted.

How are the seeds collected and stored?When stored correctly, most seeds can remain viable for decades or even for centuries.Here is the general process, as described by the Department of Environment and Conservation, The Atrium, 168 St Georges Terrace, Perth WA 6000.

First, researchers decide what seeds to collect, in concert with the seed bank's mission.

After plants are located, seed collection begins. Seeds are most viable for collection and storage when ripe. In the case of fruits, most release their seeds when ripe. However, some plants will retain their seeds for extended periods, which allows a longer collection time. Other plants might seed irregularly, and thus require repeat visits.

Researchers collect the seeds manually with tweezers, pole cutters, seed traps or nets and buckets, depending on the type of plant.

For each collection, they record details like location, plant description, habitat, soil type and other information. This information provides data about the local plant population and ensures optimal replanting conditions.

Collectors then assign each sample a unique number.

Collectors clean each sample to ensure high quality. Seeds can be cleaned by shaking them through a sieve or with a machine that blows air on them.

To reduce the moisture content of the seeds, collectors dry them in a temperature- and humidity-controlled room. Afterward, they place the seeds in sealed, airtight containers.

The final storage step is to freeze the seeds at minus 4 degrees Fahrenheit (minus 20 degrees Celsius).

Seeds are stored in labeled, air-tight aluminum foil pouches

Difficult-to-store seeds may respond better to cryopreservation, or to in-vitro storage. For example, the banana plant doesn't produce seeds, so alternative storage methods are necessary. In-vitro storage means that living plant tissues are stored, rather than seeds. Scientists then place these living tissues in liquid nitrogen--around minus 320 degrees Fahrenheit (minus 196 degrees Celsius)--to ensure better long-term storage. Although shelf life varies from crop to crop, eventually all seeds will die. Before this happens, scientists remove seeds from storage and plant them to harvest and re-bank fresh seeds.

Iowa, my home state, is also home to two important seed banks. The Seed Savers Exchange, located near Decorah, is by far the most well-known of the two. Founded in 1975, its members have saved and passed on over one million samples of rare/heirloom garden seeds to other gardeners. Heritage Farm, Seed Savers' 23-acre certified organic gardens, is open to visitors during the growing season. Each year 10% of all plant varieties kept in cold storage is planted on a 10-year rotation to renew the seed collection. A link to the Seed Savers website appears in the table at the end of this article.

The Amana Heritage Seed Bank, located at Cottage-in-the-Meadow Gardens in South Amana, is perhaps the smallest seed bank in the U.S. It's mission is to preserve and disseminate six unique vegetable varieties brought to the area by German settlers. They include a radish ('Vielfarbiger Rettich'). a string bean ('Grüne Bohnen'), a Celariac or Root Celery ('Knollecellerie'), a lettuce ('Eiersalaat'), an onion ('Ebenezer Zwiebel'), and a European Black Salsify ('Schwarzwurzel'). A link to the Amana Heritage Seed Bank appears in the table at the end of this article.

Vegetables in the Amana Heritage Seed Bank

A Sampling of Heirloom Vegetables Here at Dave's Garden

---------------------------------Click variety name to view details-----------------------------------

International Rice Research Institute LinkDAPO Box 7777 Metro Manila, Philippines Tel: +63 (2) 580-5600 Fax: +63 (2) 580-5699 Questions? Comments? Please scroll down to the form below. I enjoy hearing from readers! Related Mail Order Gardening Theme Week article: When Seed Selling Was A Seedling - a brief history of mail order seeds in the United States by Carrie Lamont. At the end of Carrie's article you will also find a listing of other articles featured during this theme week.*Ashcroft, Suzanne and Whealy, Kent, Seed to Seed, Decorah, IA: Seed Savers Exchange, 2002.

About Larry Rettig

About Larry Rettig

An enthusiastic gardener for over 50 years, my first plant was a potted Ponderosa Lemon tree ordered from a comic book ad at age 15. I still have it, and it’s still bearing lemons! My wife and I garden on 3/4 of an acre, both flowers and vegetables. Although our garden is private, it's listed with the Smithsonian Institution in its Archives of American Gardens and is on the National Register of Historic Places. We garden organically and no-till. Our vegetable garden contains a seed bank of vegetables brought to this country from Germany in the mid-1800s. For more info: http://davesgarden.com/community/blogs/m/LarryR/. Photos that appear in my articles without credit are my own.